Cleaning commercial solutions

Ammonia is widely used as a refrigerant, a fertilizer, and a household and commercial cleaning agent. Anhydrous ammonia (NH3) is a highly irritating gas that is very water-soluble. Aqueous solutions of ammonia may be strongly alkaline, depending on the concentration. Solutions for household use are usually 5-10% ammonia, but commercial solutions may be 25-30% or more. The addition of ammonia to chlorine or hypochlorite solutions will produce chloramine gas, an irritant with properties similar to those of chlorine (see p 162). 

The LC-MS/MS instrumental detection limits were roughly estimated hy extrapolation of S/B values measured for the clean standard solutions to S/B = 3, and comparisons of the results obtained using different instruments nicely illustrates the advances in ESI—MS/MS technology over the last 20 years or so. The LOD values for the 20 toxins obtained using optimized MRM on the first commercial LC-MS/MS instrument (MDS-SCIEX API in, manufactured 1988) were in the range 40-7000 nM for an injection volume of 5 p,L, but when a modem version (API 4000) was used under identical conditions the LOD range was 5-30 nM, that compares favorably with values 5-100 uM obtained (Oshima 1995) for the LC-oxidation-fluorescence method. 

Apart from industrial sources, some acids are also found in domestic settings. Sulphuric acid is found in lead-acid car batteries and some commercial solutions for unblocking drains. Dilute hydrofluoric acid is used in some cleaning solutions. 

Three important precautions are needed when working with pipets and volumetric flasks. First, the volume delivered by a pipet or contained by a volumetric flask assumes that the glassware is clean. Dirt and grease on the inner glass surface prevents liquids from draining evenly, leaving droplets of the liquid on the container s walls. For a pipet this means that the delivered volume is less than the calibrated volume, whereas drops of liquid above the calibration mark mean that a volumetric flask contains more than its calibrated volume. Commercially available cleaning solutions can be used to clean pipets and volumetric flasks. 

Ethoxylated andSulfatedAlkylphenols. Because these aLkylphenols degrade less readily than the sulfated alcohol ethoxylates, their anticipated expansion failed to materialize, although by 1965 they were widely used in retail detergent products. Sulfated alkylphenol ethoxylates are used in hospital cleaning products, textile processing, and emulsion polymerization. Sulfated alkyphenol ethoxylates are sold as colorless, odorless aqueous solutions at concentrations of >30%. The presence of ethylene oxide in the molecule increases resistance to hardness ions and reduces skin irritation. Representative commercial sulfated alkylphenol ethoxylates are given in Table 12. 

The commercial recovery of iodine on an industrial scale depends on the particular source of the element.Erom natural brines, such as those at Midland (Michigan) or in Russia or Japan, chlorine oxidation followed by air blowout as for bromine (above) is much used, the final purification being by resublimation. Alternatively the brine, after clarification, can be treated with just sufficient AgNOs to precipitate the Agl which is then treated with clean scrap iron or steel to form metallic Ag and a solution of EeU the Ag is redissolved in HNO3 for recycling and the solution is treated with CI2 to liberate the h ... 

Improved plow steel and extra improved plow steel, bright and galvanized. Use a suitable solvent to remove lubricant. The wires then should be dipped in commercial muriatic acid until thoroughly cleaned. The depth of immersion in acid must not be more than the broomed length. The acid should be neutralized by rinsing in a bicarbonate of soda solution. Fresh acid should be prepared when satisfactory cleaning of the wires requires more than one minute. (Prepare new solution—do not merely add new acid to old.) Be sure acid surface is free of oil or scum. The wires should be dried and then dipped in a hot solution of zinc-ammonium chloride flux. Use a concentration of 1 lb (454 g) of zinc-ammonium chloride in 1 gal (3.8 L) of water and maintain the solution at a temperature of 180°F (82°C) to 200°F (93°C). 

A suspension of sodium amide2 (0.1 mole) in liquid ammonia is prepared in a 500-ml. three-necked, round-bottomed flask fitted with a West condenser, a ball and socket glass mechanical stirrer (Note 1), and a dropping funnel. In the preparation of this reagent a small piece of clean sodium metal is added to 350 ml. of commercial anhydrous liquid ammonia. After the appearance of a blue color, a few crystals of hydrated ferric nitrate are added, whereupon the blue color is discharged. The remainder of the 2.3 g. (0.1 mole) of sodium (Note 2) is then rapidly added as small pieces. After all the sodium has been converted to sodium amide (Note 3), a solution of 16.4 g. (0.1 mole) of ethyl phenyl-acetate (Note 4) in 35 ml. of anhydrous ethyl ether is added dropwise over a 2-minute period, and the mixture is stirred for 20 minutes. To the dark green suspension is added over an 8-minute period a solution of 18.5 g. (0.1 mole) of (2-bromo-... 

A commercial silver alloy in the form of wire or foil is suitable for this determination. Clean the alloy with emery cloth and weigh it accurately. Place it in a 250 mL conical flask, add 5 mL water and 10 mL concentrated nitric acid place a funnel in the mouth of the flask to avoid mechanical loss. Warm the flask gently until the alloy has dissolved. Add a little water and boil for 5 minutes in order to expel oxides of nitrogen. Transfer the cold solution quantitatively to a 100 mL graduated flask and make up to the mark with distilled water. Titrate 25 mL portions of the solution with standard 0.1 M thiocyanate. 

Phenol was originally recovered during the coking of coal, essentially being a by-product. Eventually, commercial routes were developed based on benzene (from coal or petroleum) for example, sulfonation of benzene to ben-zenesulfonic acid followed by reaction with water to phenol plus regenerated sulfuric acid. Phenol is used to make plastics (phenol-formaldehyde and epoxy resins) and textile fibers (nylon). Phenol is also used in solution as a general disinfectant for cleaning toilets, stables, floors, drains, etc. and is used both internally and externally as a disinfectant for animals. 

A commercially available ultrasonic cleaner was used for the prqjaration of nickel powders from nickel salt in aqueous solution. This cleaner, Model 3210 (Branson Ultrasonic Corp., CT), is normally used as a cleaning apparatus, working at a frequency of 47 kHz with e power of 130 W that consists of a stainless-steel bath of 5.17 1 capacity and has an ultrasonic transducer attached to the bottom of the bath. A liquid solution temperature in the bath can be varied from room temperature to maximum of 80 °C. 

Pipets pose a special problem. Brushes cannot be used because of the shape of some pipets and the narrowness of the openings. If soap is to be used, one must resort to soaking with a warm soapy water solution for a period of time proportional to the severity of the particular cleaning problem. Commercial soaking and washing units are available for this latter technique. Soap tablets are manufactured for such units and are easy to use. 

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